Isobutane

Synonyms

1,1-Dimethylethane; 2-Methylpropane; Propane, 2-methyl-; R 600a; Trimethylmethane; [ChemIDplus]

Category

Aliphatics, Saturated (<C12)

Description

Colorless gas with a slight gasoline or natural gas odor; [HSDB]

Sources/Uses

Used as a fuel, a refrigerant, a propellant, and a gasoline additive; Used to calibrate instruments and to make other organic chemicals; [CHEMINFO] Used as an aerosol propellant and fuel source; [ACGIH]

Comments

In mice causes CNS depression at 15% for 60 minutes or 23% for 26 minutes; In dogs causes anesthesia at 45% for10 minutes. [HSDB] In rats, the LC50 (15 minutes) was 57%, "although the lack of oxygen likely contributed to the deaths of these animals." TLV Basis is CNS impairment; Volunteers exposed to 500 ppm 8 hours/day, 5 days/week for 2 weeks had no significant adverse effects; [ACGIH: Butane, isomers] Isobutane is in the list of "Some volatile substances which may be abused by inhalation" published on the web site of the U.N. International Drug Control Programme, indicating its potential to cause narcosis in workers. [Reference #1] See "n-Butane" and "Cyclobutane."

Reference Link #1

Biomedical References

Insufficient data

1000 ppm

1000 ppm (for Butane, isomers)

2610 mm Hg

LC50 (rat) = 570,000 ppm/15 min

Explanatory Notes

"Explosion Hazard." [TLVs and BEIs] VP from ChemIDplus;

burn readily

Acute solvent syndrome

Other Poison

Simple Asphyxiant

Diseases

Occupational diseases associated with exposure to this agent:

• Asphyxiation, simple
• Solvents, acute toxic effect